A device which controls the voltage and current being delivered to a capacitor or battery.

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1answer
47 views

Issue charging a 12V battery using solar charger

I bought a 12V solar charger for vehicle batteries, because I am usually using wall chargers and I wanted to give green technology a try. When I connect the solar charger to my battery, it shows 10V, ...
2
votes
1answer
492 views

How can I extend this circuit to use it in our real life?

I am planning to design a wireless mobile charger circuit next week. For that purpose, I have selected the circuit which is shown below and is collected from the post: wireless mobile battery charger. ...
2
votes
2answers
65 views

Supercap charging circuit for RTC backup on STM32

I'm asking for a reliable/simple/cheap circuit for the VBAT section of a STM32 design, powered at VDD=3.3V, that will safeguard the built-in RTC (based on 32768 Hz Xtall) for like 10 days. Based on ...
1
vote
4answers
115 views

Battery-Operated Mobile Charger

I want to build a mobile charger that is battery operated and found this diagram. At first glance, this diagram looks kinda simple and I thought that this won't work. I'm a newbie on making this kind ...
1
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3answers
135 views

Rate my Rasberry Pi UPS

I've made simple schematic for a UPS for Raspberry Pi. It contains a 12V Lead Acid Battery (40Ah), 5V LM7805 regulator and some capacitors. I'm supposing max 1.2A load from Raspi. Should I add ...
2
votes
2answers
65 views

How to reduce voltage of a dynamo to 5 volts

A friend and I are going to make a bike-powered charger. There is a video of KipKay making one. But he uses a 12 volt 6 watt dynamo and there is a schematic that he follows to lower it to 5 volts. Can ...
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votes
1answer
57 views

How to fix exposed wire at the end of a laptop charge with electrical taper [closed]

I have a Toshiba L505D-S5965 with Windows 8.1. My charger has exposed wire at the end but it was working until a few days ago. It's at the part where it's plugged to the laptop charger port. Now it ...
0
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3answers
76 views

Method to lower voltage of a laptop charger

I bought an IMAX B6 LiPo Balance charger that needs as input 11-18V but I have an unused laptop charger (the laptop is gone) having 19V with 4.74A. What is the easiest method to lower the voltage to ...
0
votes
2answers
85 views

Charging supercapacitors with Buck converter. Do I need to cut power once charge is reached?

I am trying to build a supercapacitor charger, and as I don't particularly have a good handle on the risks of such a thing, I'm hopping on here to give some information. I am using a buck converter ...
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votes
1answer
73 views

how to increase output current? [closed]

I have several car chargers but all have 5v, 500-800mA output current. I want to increase the output current to 1A. So that my cell phone charges quickly. Help me what to change or add component to ...
1
vote
1answer
65 views

Question on 3DS power adapters, minor voltage difference [duplicate]

I am going to be traveling overseas and bringing my Nintendo 3DS which the adapter outputs DC 4.6V 900mA. I found an unofficial USB cable to charge it and I was curious if the minor variance in the ...
0
votes
3answers
97 views

Will a dual car charger that shows a maximum output of 2000mA produce a 2.1A current?

I have a dual car charger that states input is 12-24VDC and Output is maximum of 2000mA, but it is supposed to have one port charge at 1A and other port charge at 2.1A. Is the 2.1A output possible ...
0
votes
4answers
95 views

What is this electronics component?

What is the yellow component shown here? This is off a Outlet USB phone charger.
0
votes
1answer
56 views

LiPo Charger question [closed]

I'm not into electronic so this is why I ask people who know. I have an opportunity to buy a 5,000 mAh LiPo charger but I will use it to charge up to 14.8V 8,000 mAh batteries. Will it charge the ...
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votes
1answer
35 views

What is a good NiMH charger? [closed]

I have some (cheap/old?) batteries that I need charged. The problem is, the chargers I have keep charging them until they get overcharged and lose their capacity. I already ruined 4 ...
1
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2answers
80 views

Why one transistor switches on first than other

In the circuit diagram given below we have two transistors. And in the article it is given that one transistor will turn on first. Why this transistor turns on first
0
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0answers
52 views

homemade hub dynamo usb charger

I just made an usb charger to connect to my hub dynamo. ->voltage rectifier -> smoothing capacitor -> low voltage drop 5V regulator -> female usb port So now I can power / charge my mobile phone and ...
1
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4answers
121 views

Will voltage or current determine a diode drop for this battery charging circuit?

I am using a li-ion battery charger IC that regulates an output to 4.2V. I have a schottky diode in series with the output that then connects to the battery. How do I determine the voltage drop? If ...
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votes
1answer
83 views

What do B+ and C+ mean on the wires of a Lifepo4 battery pack?

I bought this Lifepo4 battery pack. It came with its own charger. The seller told me the charger can be connected directly to the battery. There are 4 cables coming out of the battery: C+, C-, B+ and ...
1
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1answer
94 views

Efficient power utilization by MPPT battery charger

I am designing an MPPT solar charge controller to get more efficiency out of my system. At the moment I am at the conceptual stage and I have some questions about MPPT battery charging in general. ...
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votes
1answer
141 views

Transmitting 12v DC over a long wire

I'm trying to charge my laptop through a 12V battery and 12-19V adapter over a long wire but I've noticed that the adapter makes some noise and doesn't work. On the other hand when I connect it close ...
0
votes
2answers
63 views

DC output of phone charger [duplicate]

I have a nokia phone charger which has the following specifications: Input: AC 100-240 V, 50-60 Hz, 100 mA Output: DC 5.0 V, 350 mA When I checked the output of the charger with a multimeter it ...
0
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0answers
73 views

LiPo combination usb/dc/solar charger + fuel monitor

I'm trying to roll several LiPo boards available on Sparkfun/Adafruit into one multipurpose board. Not a very ambitious project I know, but I'd really like an all in one. I've seen Sparkfun's LiPo ...
0
votes
1answer
57 views

Can someone tell me if this topology for a crude battery charger is sound? Block diagram included

I am making a portable phone charging battery for fun. I have a micro USB input that ties to a 5V - 4.2V buck converter to charge a li-ion battery. The IC is made to charge batteries so I think that ...
0
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1answer
101 views

Can I use a 7805 as a current regulator?

Can I use 7805 as current regulator? My input is 12-14 V DC (battery) and I require output 5V and 500mA or adjustable. My background is CS so unaware of these ICs. I have searched LM317 and LM338 but ...
2
votes
2answers
243 views

Is it ok to use an old phone as an universal battery charger?

We know that a charger is just an adapter that supplies a constant voltage (5 volts usually). The actual charging circuit is in the phone itself. With a bit of soldering and wiring, can I use my old ...
0
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1answer
125 views

Battery charging: Absorption Charge Stage

I need some help in understanding basic battery charging. I read about the three common stages: Bulk Charging, Absorption Stage and Float Stage, but I can't understand exactly what the controller does ...
2
votes
1answer
121 views

LiPo use while charging: two cells (one charging, one under load)

I'm trying to figure out how to power my project using LiPo batteries and a solar charging circuit. The project will draw up to 2A at 3.3V. I did a search for IC LiPo charging chips that also allow ...
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2answers
98 views

Charging 12V SLA from Single Solar Cell

I'm interested in charging a 12V Sealed Lead-Acid battery from a single monocrystalline solar cell. The solar cell's voltage is only 0.5V at maximum power point, but it supplies 8A. I will need a 32X ...
0
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1answer
87 views

Trigger charge in Android phone using a PIR

I want to use my android phone + 1 PIR as a poor man's home alarm. I need the phone to be triggered somehow when the PIR detects motion. I was looking at the IOIO board. But wouldn't even be easier ...
1
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1answer
103 views

Is the DESIGN of an MPPT Solar charger SUPPORTING combination with regular battery charger on the LOAD side? [closed]

I just got my "LCD 30A MPPT Solar Panel regulator" for my caravan, but connecting it raised an issue. It looks like this: ...
2
votes
2answers
262 views

How do we charge a small 12V battery from a large 12V battery bank

In a youth organization that I am part of we are building a traveling stand alone system, which will be put up on various fairs and music festivals. On one of the festivals there is a wish that we can ...
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3answers
100 views

Please help me understand this charging algorithm

I am trying to plan a stand alone system, and for that I will need a charge controller. I am looking at a few models from the company MorningStar. I have understood what MPPT is, and decided to not ...
1
vote
1answer
177 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
0
votes
1answer
55 views

ICSwitching between solar panel and batteries

I would like to charge the NiMH batteries, when there is excess power from the solar power and use the power stored in the batteries, when I need it (to drive a motor and at night). I have the ...
0
votes
2answers
102 views

What are the downsides of using a LM7805 with a 11.1v Li Ion Laptop battery to charge a USB device?

I want to use my thinkpad battery(11.1v) hooked up to a LM7805 to charge a USB Device. What are the downsides to such a setup?
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3answers
419 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
0
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1answer
72 views

What does 'Braked Voltage' mean on a charge controller?

Here is the complete specs of the controller. Battery rated voltage: 12v Wind turbine rated power: 300w Wind turbine braked voltage: 15v Recover voltage: 13.5v Quiescent dissipation: <8ma ...
0
votes
1answer
73 views

POWER SUPPLY / CHARGER [duplicate]

I have a 14.4v NI CD power drill with a charger that outputs 18v 400mA (original charger for drill) but the charger supply lead no longer works. Looking to get a replacement but finding it difficult ...
0
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1answer
86 views

Charging of Cell Phone Batteries and Electricity! [closed]

Does charging an already charged battery of cell phones/laptops consume electricity? Whenever my cell phone becomes fully charged while charging, it asks me to remove the charger from the socket to ...
0
votes
1answer
125 views

Multi port usb charger

I want to make a multi port usb "dumb hub" kind of like this. My question though is if I have a 5v 2500mA power supply, can I just daisy chain them together with out the fuses then connect it to the ...
1
vote
2answers
76 views

Need to charge a lithium power pack from USB

I need to charge a small lithium power pack from a device that was originally charged using a 5v USB connection. The connector on the device is damaged so I need to charge the power pack directly. ...
0
votes
1answer
291 views

Powering circuit from 12V with stand-by battery + solar charger

I did some research but I haven't been able to find the information that I really want. I am building a home made security system consisting of several IP cameras. Brownouts are very frequent so I ...
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votes
1answer
93 views

humming of a mobile phone charger [closed]

Why do a mobile phone charger (without mobile phone attached to it) constantly hums when kept plugged into A.C. outlet and the moment mobile phone is plugged into charger, humming goes. Why so ?
5
votes
3answers
729 views

How to make a voltage multiplier of 1.075

I have an 80v power supply that's rated to put out 18 amps, and I'm planning on using it to charge an 80v battery pack. Unfortunately the pack's charge voltage is 86v, so what I'm wandering about is ...
0
votes
1answer
97 views

How can I disconnect a Battery Charger from the Battery while not Charging

I have a LiIon Battery Charger IC which will draw around 50µA when not needed, see circuit 1. This is a lot of current for no work in my opinion. Now I search for a solution how I can disconnect the ...
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0answers
58 views

Why does the QI charger I recently bought only charge for a couple of times? [closed]

I recently bought a QI compatible charger for my Nexus 5. On the box it states, that the wireless charges up to 500 times. I don't understand why the charger is only able to charge my phone 500 times. ...
3
votes
2answers
174 views

What might cause audible noise in an inductive charging system?

I have a pair of Qi-compatible wireless charging pads, and I've noticed that when a device is charging, the pad will emit a quiet but noticeable squeal in a relatively high frequency range. Perhaps ...
3
votes
1answer
104 views

How do I smooth current dips on a USB charger?

I've got a USB charger that I want to use to charge a phone. For about 35 seconds it outputs enough current for the phone to detect it and start charging, then for an instant (no equipment to read ...
4
votes
2answers
248 views

Hacking wall wart as a USB charging station

I would like to modify an old power supply to have a USB A female adapter so that I could use it to charge any device. I plan to split out the power lines from an adapter that is: Input: 100-240V - ...